Questions

Flag is a flip-flop used to store the information about the status of a processor and the status of the insturction executed most recently.

A software or hardware mark that signals a particular condition or status. A flag is like a switch that can be either on or off. The flag said to be set when it is turned on.

Static RAM: no refreshing, 6 to 8 MOS transistors are required to form one memory cell, information stored as voltage level in flip flop. 

Dynamic RAM: refreshed periodically, 3 to 4 transistors are required to form one memory cell, information is  stored as a charge in the gate to substrate capacitance.

The system board is also known as the Mother board, Main circuit board, Baseboard or logic board.

Yes, single thread module

Acceleration is nothing but the rate at which velocity changes over time.